diff --git a/poincare/src/expression_layout_cursor.cpp b/poincare/src/expression_layout_cursor.cpp
index 748c8425c..18ae81332 100644
--- a/poincare/src/expression_layout_cursor.cpp
+++ b/poincare/src/expression_layout_cursor.cpp
@@ -85,7 +85,7 @@ void ExpressionLayoutCursor::addFractionLayoutAndCollapseBrothers() {
     rightBrother = newChild->editableParent()->editableChild(fractionIndexInParent+1);
     if (rightBrother->isCollapsable(&numberOfOpenParenthesis, false)) {
       newChild->editableParent()->removeChildAtIndex(fractionIndexInParent+1, false);
-      child2->addOrMergeChildAtIndex(rightBrother, child2->numberOfChildren(), false);
+      child2->addOrMergeChildAtIndex(rightBrother, child2->numberOfChildren(), true);
       numberOfBrothers--;
     } else {
       break;
diff --git a/poincare/src/layout/horizontal_layout.cpp b/poincare/src/layout/horizontal_layout.cpp
index af9875390..43a7fae89 100644
--- a/poincare/src/layout/horizontal_layout.cpp
+++ b/poincare/src/layout/horizontal_layout.cpp
@@ -278,12 +278,12 @@ bool HorizontalLayout::moveDown(ExpressionLayoutCursor * cursor, bool * shouldRe
 }
 
 void HorizontalLayout::addChildrenAtIndex(const ExpressionLayout * const * operands, int numberOfOperands, int indexForInsertion, bool removeEmptyChildren) {
-  int newIndex = removeEmptyChildBeforeInsertionAtIndex(indexForInsertion, operands[0]->mustHaveLeftBrother());
+  int newIndex = removeEmptyChildBeforeInsertionAtIndex(indexForInsertion, !operands[0]->mustHaveLeftBrother());
   DynamicLayoutHierarchy::addChildrenAtIndex(operands, numberOfOperands, newIndex, removeEmptyChildren);
 }
 
 bool HorizontalLayout::addChildAtIndex(ExpressionLayout * operand, int index) {
-  int newIndex = removeEmptyChildBeforeInsertionAtIndex(index, operand->mustHaveLeftBrother());
+  int newIndex = removeEmptyChildBeforeInsertionAtIndex(index, !operand->mustHaveLeftBrother());
   return DynamicLayoutHierarchy::addChildAtIndex(operand, newIndex);
 }